1. Field of Invention
This invention concerns the formulation and processing of fermentation byproducts into useful feed products.
2. Description of Related Art
In the animal agricultural industry, a great deal of effort has been placed into providing nutritional high quality feed materials. Fermentation byproducts have been fed to domestic animals for hundreds of years in both in wet and dried form. Fermentation processes tend to concentrate nutrients in the by-products, such as, for example, corn, wheat, and/or barley, by using up the fermentable carbohydrates. Some vitamins and other nutrients are increased by the (yeast) fermentation process. For example, corn, which contains about 8% crude protein, is increased to a protein level of about 22% to 28%, on a 12% to 13% moisture level. Fat and fiber in spent corn are also typically increased to at least double their original levels through concentration.
Corn is a good candidate for fermentation due to its relatively high carbohydrate content. However, the low protein content of the grain in general, and its low content of the amino acid lysine, leads to low levels of these nutrients in the spent grain.
The spent grain has traditionally been sold to the animal feed industry as a product known as “distillers dried grain w/sol(DDGS)”, “distillers dried grains (DDG),” and “wet distillers grains (WDG),” or “wet brewers grain (WBG),” and “dried brewers grain (DBG).” With much of the carbohydrate used up in the fermentation process and the relatively low levels of protein and energy, fermented grain has been of little interest to the poultry and swine industries. As a result, the majority of the fermentation byproducts from distillers and brewers, e.g., fermented grains, have been used as feeds for ruminants, including dairy cows.
In today's modern dairy operations ruminant animal rations are formulated with different ingredients to provide precise levels of degradable protein to the ruminant animal rumen bacteria and rumen undegradable protein (RUP) (also referred to as UIP or undegradable intake protein) in the ruminant animals' lower gastrointestinal tracts. Animal rations are also balanced to provide known levels of specific amino acids to the animals' lower gastrointestinal tracts.